Milk-testing tube.



H. JONE.

MILK TESTING TUBE. I APPLICATION FILED NOV- 9,1915" 1,16-8,64;&, "Patented Jan. 18, 1916.

" GREECE.

HUGO JONE, or nnooxnyn, new YORK.

MILK-TESTING TUBE.

Llfig figi Specification of Letters Patent. Patented Jmm 18, 1916 Application filed November 9, 1915. Serial No. 60,616. To all whom it may concern: ture since the amount of oxygen absorbed Be it known that I, HUGO J ONE, a citizen by the mixture from the air is not always the of the United States, and a resident of same when air is admitted. Under these cir- Brooklyn, New York, have invented certain cumstances it is quite evident that the exclunew and useful Improvements in Milksion of air is-most desirable for the purpose Testing Tubes, of which the following is a of getting correct results. It is also evident specification. l that the cream which separates at the top of My invention consists substantially of a the liquid has to here-mixed with the rest;

milk testing tube which is provided with a 0f the liquid, since otherwise, the numerous 5 capillary tube chiefly for the purpose of" bacteria contained in the cream would not separating the air from any oxidizable reparticipate in the reduction of the methylene agent which may be contained in the testing blue for the reason that there is no methylene tube together with the milk to be tested, in blue left 1n the white layer of cream which the reductase test or in a similar test, the settles at the top. The duration of the test separation to be efl ective even if the testing Would'therefore be unduly prolonged. To,

tube is inverted for the purpose of re-mixing accomplish both purposes, viz: to exclude" the cream with the rest of the milk. In ad the alr and to permit the re-mixing of the k I;

dition to the capillary tube means may be cream with the rest of the. liquid, the capil-v provided for the purpose of mixing the conlarytube isused. tents and for performing other usefulfunc- The'test is made as follows: 30.0 cubic tions which are desirable in the reductase centimeters of the well mixed milk audit 2 test and similar tests. measured volume. of thewwell preserved The new milk testing tube is illustrated by methylene blue solution of known strength,

the accompanying drawing. generally 4.0 cubic centimeters, are introg Referring to the several views of this duced into the testing tube which on the .1 drawing: Figure 1 is a side elevation of the drawing is identified by number 10. Glass new testing tube with part of the front wall beads 15, preferably of globular form and removed to show the interior. Fig. 2 is a about; 6 millimeters in diameter are then vertical cross section of the upper part of allowed to drop into the liquid single or in said testing tube on an enlarged scale. Fig. groups, as may be necessary until the liquid 3 is a horizontal cross section of said testing rises to nearly the top of the testing tube. tube on line 33 of Fig. 2, seen in the direc- The perforated rubber'stopper, 12, with the tion of the arrows. Fig. 4 is a horizontal capillary tube 11,-having a bore, 19, of about cross section of said testing tube on line 44 1% millimeters, diameter, inserted in it, is of Fig. 2, seen in the direction of the arrows. then inserted loosely in the mouth of the The necessity of devising a milk testing testing tube, 10, in such a way that the air tube which would answer the purpose of exin the testing tube, 10, or nost of it, escapes cluding the air from the mixture of milk through the bore, 19, ofthe capillary tube, and methylene blue solution in the reductase 11, while the testing tube, 10, isicl'osed'sufiitest is apparent from statements which I ciently tight to permit the mixing of the made in the pamphlet entitled: An Easy contents without any loss of liquid. The Test for Bacteria in Mills and Cream, Bet mixing of the liquid is accomplished by in- 'r/teZs Reductase Test, Improved by Hugo vertin the testing tube,'10, in such a way Tone, 1915. As this work has been pubthat the glass beads drop to the stopper o ished, there seems to be no need of my de end of the testing tube, then inverting it cribing in detail the errors resulting from again to have them drop back, and repeat- .dmission of air to the mixture. I will howing the operation until they have dropped ver briefly point out the two principal through the liquid 6 or 8 times. The stopper auses of thoseerrors. 12, is to be lifted out of the mouth of the 10,,

The leuco compound formed from the testing tube, 10, if any of the unmixed liquid lethylene blue by reduction readily takes up should have been forced intothe bore, 19, of l xygen from the air, thereby restoring the the capillary tube, 11. This is done for the lethylene blue and prolonging the test bepurpose of having such liquid drop back to and the proper duration. The aerobic orthe remaining liquid in the testing tube,

inisms sometimes get a good chance and since the loss of any unmixed liquid would 'metimes a poor chance-to grow in the mixmake the test inaccurate. After the liquid is thus thoroughly mixed, the stopper, 12, can be inserted more firmly than it was in serted the first time for the reason that the loss of a small amount ofthe liquid can now no longer do any harm, since it could not, under these circumstances, affect the duration of the test. It'is even desirable to'insert the stopper the secohd time with sufficient force to eject a little of the liquld through the bore, 1 of the capillary tube, 11, because in this way the removal of the last remaining air bubbles may be accomplished. The stopper is then raised slightly to have the milk mixture in the bore drop to about the middle of ,the capillary tube. After the liquid is thus deprived of air and thoroughly mixed, and the height of. the liquid in the bore regulated, the test is started by putting the tube in a water bath or air bath or oil bath kept at the temperature of 45 centigrade or 375 centigrade or at some other incubating temperature, as may be desired. The cream, 13', which rises at the top is re-mixed with the remaining 'formed 'a' pale blue or colorless layer of liquid, ll every time that it isfound to have sufiicient' amount to afiect the result of the test. Thisis continued until the decolorization of the methylene blue is completed, and the time required for it, is determined.

In order to make sure of removing all the air bubbles the rubber stopper, 12, may have a hood shaped cavity, 16,- at the bottom, which causes the air bubbles to pass into the pocket 17., This pocket, 17 is formed by inserting the capillary tube, 11, into the hole of the perforated rubber stopper, 12, in such away that its lower end does not reach 'the bottom of the rubber stopper, 12, but remains-a few millimeters above that bottom or above the cavity, 16, at the bottom. In order to facilitate the proper insertion of the'capillary tube into the rubber stopper, 12, the former may be provided with a collar, 18, so it will slip in no farther than to the proper point.

,As' the reductase test may bemadewith more-or less methylene blue solution than 4: 00., the size of the testingtube may be varied accordingly. It may have a capacity as small as cubic centimeters or as large as cubic centimeters' The former size would be suitable, if only 1 cubic centimeter of methylene blue solution is used, while the latter wouldv be suitable if as much as 10 Cl1b10 centimeters are used; In either case,

- it is understood that the amount of milk used is 30 cubic centimeters. If less milk is taken, for instance 10 cubic centimeters and. only one third the amount of the methylene blue solution which would be taken for 30 cubic centimeters of .milk, the testing tube may certainlyfbe made correspondingly smaller. a

The testing tube is preferably made of highly transparent, colorless glass so the It may be 20 centimeters. long.

suitably inserted in the rubber stopper. The

inside diameter of the capillary tube may be decreased to l millimeter or it may be increased to 2 millimeters without materially changing the mode of operation. If however, the inside diameter is increased to 3 millimeters, it is desirable to close the open end of the capillary tube with a finger at the moment when the testing tube is inverted for the purpose of mixing the contents, so as to prevent the possible introduc-' tion of air into the testing tube. vWhen operating with the ordinary capillary tube of 1%- millimeters diameter, or a still smaller diameter this precaution will be 'found unnecessary. If the inside diameter is increased much beyond 3 millimeters, a part of the cream, when rising, may settle in the tube and fail to remix with the rest of the liquid when the contents are mixed. As this is not desirable for the reason that the sepa rated cream cannot exercise its full reducing power on the methylene blue in the liquid, unnecesarilylarge, inside diameters are avoided. The length of the capillary tube is subject to considerable variation. It may be decreased to 10 centimeters, more especially if the inside diameter is more than 19; millimeters. It may be increased to 30 centimeters, more especially if the inside diameter is less than 1?, millimeters. The collar, 18, may be replaced by three or four smallglass cor s fused on the capillary tube at the same point, since such glass cones or similar protuberances would prevent the capillary tube from slipping too far into the rublieir stopper just asefi'ectively as a collar wou The outside diameter ofthe capillary tube y can certainly be varied considerably, the object of havinga thick tube being merelv that of making it'dura'ble. H

The glass beads, when dropped in one by one evidently otter the'advantage that they raise the liquid gradually, not suddenly. The diameter of the glass. heads is gen .erally about 5 millimeters. However, it may be as small as 2 millimeters-ores large as 8 millimeters, .The globular beads are pre-.

ferred to others, but they may have other.

forms. Milk white beads are preferred to others, as they show foreign colors better. Shot like balls of nickel. or of tin ma be substituted for the glass-beads vif deeir'ed.

The testing tube is not to beused eXclu-;

sively for the ordinary reductase .test, but for a number of modifications of that test. For instance, the fermentation of the milk may be'omitted. The reductase originally present in the milk sample may be determined by the extent of deco'lorization eifected within a-few minutes, and therefore without any material fermentation; The tube may be applied to all cases where the reductase is measured by tho decolorization of the methylene blue. The testing tube is also capable of application to heterogeneous liquids other than milk when they contain a sub stance which is deteriorated by atmospheric oxygen. 'As such liquids would also separate two or more layers on settling, they may also require to be re-mixed, which could again be done by inverting the testing tube.

. Attention is called to the fact that the liquidin the testing tube when it is inverted,

is prevented from dropping out not merely by the barometric pressure of the air, but

also by capillary attraction, or surface ten-,

sion. The liquid couldcertainly be prevented from dropping out of the testing tube byclosing it with a glass disk and a-screw cap 'in the same way as the inside tubes of polari- 40 scopes are closed. However, as this method -requires considerable time and a somewhat complicated apparatus, the method with the capillary tube is decidedly preferred. The hood shaped cavity at the bottom of the rubber. stopper could certainly have a shape other than tha of a hood or of a coneand still answer the purpose of causing the ,air to rise unto the bore of the capillary. Furthermore, by using a beveled stopper and omitting the cavity alto l gether, a similar efiect con (1 be obtained.

The testing tube is certamlynot applicable to the determination of the reductas'e by methylene blue merely, but to its determination by any similar coloring matter.

as well. Indigo-carmine, safranin, various imido-quinones, indogenid, and other sub-' stances which are easily reduced and easily re-oxidized could .be substituted for the methylene blue with-more. orless success. Furthermore, the testing tube may be used in cases where not the reductase, but a similar enzym is to be determined in milk, in fact, it can be used if an entirely different ingredient of the milk is to be determined so lon as a reagent is introduced into the milk, in'such a test, which is deteriorated by atmospheric oxygen. Likewise the tube may be used for any bacteriological determination involving the cultivation of anaerobic organisms in the absence of atmospheric oxygen.

Claims:

1. A milk testing tube the interior of which is connected with the outside air by a capillary tube inserted in a rubber stopper which, in turn, is inserted in an opening of the testing tube and the bottom surface of which is sloping in such a way that the opening of the capillary bore is .the highest point.

2. A milk testing tube the interior of which is connected with the outside air by a capillary tube and which containsglass beads of a milk white color. 3. A" milk testing tube containing glass beads and the interior of which is connected with the outside air by a capillary tube inserted in a rubber stopper which, in turn, is inserted in an opening of the testing tube and the bottom surface of which is sloping ;in such a way that the opening of the capillary, bore is the highest point.

' 4'. A milk testing tube containing milk white glass beads and the interior of which is connected with the outside air by a capillary tubefi inserted in a rubber stopper which, in turn, is'inse'rted in an opening of the testing tube.

- HUGO J ONE.

WVitnesses: V

ISABEL LEvmsoN, FRIEDA KICK.

Copies of this patent may be obtained for live cents each, by addressing the Commissioner of Patents. Washington, D. p." 

